ASHRAE Journal - March 2022 - 47

COLUMN RESIDENTIAL APPLICATIONS
Children have respiratory systems that are still developing
and are thus more vulnerable, inhale more air per
pound of body weight and are often more active and
spend more time outside than adults.18 During pregnancy,
women experience higher respiratory rates; this
and other physiological changes may make them and
their developing fetuses more vulnerable.19 - 21 Aging
adults may also be more susceptible due to higher incidence
of chronic disease and natural decline in lung
function as they age.11
The impacts of wildfi re smoke are not equal across
the socioeconomic spectrum. Some research has found
that areas with the lowest socioeconomic status are at
the greatest risk of adverse effects,22,23 including indigenous
populations. The reasons for this are complex,
but include underlying health conditions, leakier buildings
allowing more smoke infi ltration and lack of air
conditioning forcing occupants to open windows for
ventilation and cooling. Renters are in a particularly
challenging situation because they suffer from the hazards
of wildfi re smoke but must rely on owners to pay
for improvements to the building, though some steps to
reduce smoke exposure may be within renters' control.
ASHRAE's Response to the Increasing Wildfi re
Smoke Hazard
In response to these concerns, ASHRAE initiated
the development of Guideline 44P, Protecting Building
Occupants from Smoke During Wildfi re and Prescribed Burn
Events. While Guideline 44P is still in development,
the committee developed interim guidance, " Planning
Framework for Protecting Commercial Building
Occupants from Smoke During Wildfi re Events. " 24 The
scope of Guideline 44P and the Planning Framework
document are primarily for commercial buildings. Since
addressing wildfi re smoke hazards for dwelling occupants
is also critical, the ASHRAE Residential Buildings
Committee (RBC) published a Residential Issue Brief
(RIB) titled " Wildfi re Smoke Hazards for Dwelling
Occupants " 25 in June 2021.
The RIB recognizes that ASHRAE is uniquely qualifi ed
to provide guidance on building performance and the
design, operation and maintenance of HVAC systems to
help protect occupants from exposure to wildfi re smoke.
ASHRAE RBC is initiating an effort to pursue an RIB
recommendation for ASHRAE to consider developing
appropriate engineering interventions and operational
recommendations to help protect dwelling occupants
from the impacts of wildfi re smoke for the building
envelope, new construction practices, existing HVAC
systems, existing structures in poor condition with high
infi ltration rates and enhanced fi ltration and fi lter
maintenance.
The ASHRAE RBC effort is expected to take the form
of a best practices guide that will discuss the roles of
residential building envelopes, HVAC systems, fi ltration,
IAQ sensors and portable air cleaners in detail and
provide recommendations for their design, selection,
operation and maintenance in both new and existing
residential buildings. The guide will also emphasize the
importance of having a smoke readiness plan including
having necessary supplies such as replacement fi lters
and portable air cleaners on hand.
While no such guide for dwellings currently exists,
much fundamental and practical knowledge can be
found in sources ranging from scientifi c literature,26 - 29
online resources,30 - 35 and elsewhere. However, many
of these resources do not give specifi c actionable recommendations,
particularly for addressing a building's
envelope and HVAC system. There are also specifi c
issues that may require more research, such as the
impact of exhaust ventilation on indoor-to-outdoor
(I/O) ratios of PM2.5 from wildfi re smoke.
An Example from the Pacifi c Northwest
The Pacifi c Northwest (PAC) was always a predictable
place: green, gray and wet. The norm in the upper west
coast used to be that summer never started until after
July 4th, but that's changed in the past 20 years. The
PAC now experiences short shoulder seasons and hot,
dry summers with heat domes and signifi cant wildfi re
events. In September 2020, the Riverside and Beachie
Creek fi re complexes caused signifi cant air quality
issues in Portland, Ore., when Air Quality Index (AQI)
levels far exceeded 500, and elevated PM2.5 lasted nearly
two weeks, making Portland, Ore., the city with the most
polluted outdoor air in the world for a few days.
Using low-cost sensors used in a recent DOE Building
America fi eld study, two Pacifi c Northwest National
Laboratory researchers instrumented a leaky, 2,600 ft2
(242 m2) home built in 1928 in Portland for a week of
monitoring over Sept. 12 - 19, 2020, setting up indoor
and outdoor stations to collect 2 min. time-resolved
PM2.5 data. Windows were kept closed, and the three
M A R C H 2 0 2 2 ashrae.org ASHRAE JOURNAL
47
http://www.ashrae.org
ASHRAE Journal - March 2022

Table of Contents for the Digital Edition of ASHRAE Journal - March 2022
